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United States Patent |
5,232,224
|
Zeider
|
August 3, 1993
|
Golf club head and method of manufacture
Abstract
A golf club head of the metal-wood type is made from several components
welded together along parting lines. A head base has a sole plate formed
integrally with a heel, toe and back wall for the club, and has open front
and upper faces across which a face plate and crown plate, respectively,
are welded. The base, face plate and crown plate are all stamped sheet
metal parts. A hosel tube projects upwardly at a desired lie angle from
the base through an opening in the crown plate. The various parts are held
together at selected loft and lie angles in suitable holding fixtures
before being welded in place, so that heads can be custom made with
different head geometries using the same basic tooling.
Inventors:
|
Zeider; Robert L. (487 Calle San Pablo, Unit B, Camarillo, CA 93012)
|
Appl. No.:
|
932713 |
Filed:
|
August 18, 1992 |
Current U.S. Class: |
473/345; 228/170 |
Intern'l Class: |
A63B 053/04 |
Field of Search: |
273/167 H,167 K,80.1-80.8,169,173,167 F,167 G,167 J
|
References Cited
U.S. Patent Documents
1235922 | Aug., 1917 | Pittar | 273/80.
|
3819181 | Jun., 1974 | Mills | 273/80.
|
4438931 | Mar., 1984 | Motomiya | 273/167.
|
4762322 | Aug., 1988 | Molitor et al. | 273/167.
|
4874171 | Oct., 1989 | Ezaki et al. | 273/167.
|
Primary Examiner: Millin; V.
Assistant Examiner: Wong; Steven
Attorney, Agent or Firm: Brown, Martin, Haller & McClain
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 07/742,027 filed
Aug. 8, 1991 now abandoned, which was a continuation in part of
application Ser. No. 07/468,223 of the same Applicant, which was filed on
Jan. 22, 1990 now abandoned.
Claims
I claim:
1. A golf club head, comprising:
a plurality of components welded together in assembled relation to define a
hollow golf club head of the metal-wood type;
the components comprising a head base having a sole plate, heel, toe and
back wall for said club head, the base having an open front face and a
substantially flat open top face, the open front face having a lower edge
and spaced side edges each comprising flat, forwardly-facing edges, the
side edges terminating at a junction with the open top face, a face plate
welded across the open front face of said base, a crown plate having a
smooth upper surface with no protrusions welded across the open top face
of said base, and a hosel tube secured to project upwardly from the crown
plate at any one of a range of possible angles to the crown plate;
the flat side and lower edges at the open front face comprising means for
being machined to a selected loft angle;
the crown plate having an opening at its outer peripheral edge adjacent the
heel of said base;
the hosel tube extending through said opening into the interior of the
head, the opening being of predetermined dimensions greater than the
diameter of said hosel tube by a predetermined amount to leave a clearance
between the opening and hosel tube to allow a predetermined amount of
tilting of said hosel tube for angular adjustment of the hosel tube prior
to welding to the head;
The hosel tube being welded around its periphery to the opening in the
crown plate at the selected angle; and
the base, face plate and crown plate all comprising stamped sheet metal
parts.
2. The head as claimed in claim 1, wherein the crown plate is substantially
flat and fits flat against the open top face of the base.
3. A method of making a golf club head of the metal wood type, comprising
the steps of:
stamping a head base from sheet metal material, the head base comprising a
sole plate formed integrally with a heel, toe and back wall and having an
open front face and a substantially flat open top face, the open front
face having a lower edge and spaced side edges each comprising a flat,
forwardly-facing edge, the side edges each terminating at a junction with
the open top face;
stamping a face plate to conform to the shape and dimensions of the open
front face of the base;
stamping a crown plate to conform to the shape and dimensions of the open
top face of the base, said crown plate having a smooth upper surface with
no protrusions;
machining the side and lower edges of the open front face to a selected
loft angle;
securing the face plate to the open front face of the base at the selected
loft angle;
adjusting the angle of a hosel tube relative to the top face of the base to
a selected angle within a predetermined range, and positioning the hosel
tube to project into the base at the selected angle; and
securing the crown plate and hosel tube to the base with the crown plate
extending across the open top face of the base and the hosel tube
projecting upwardly from the crown plate at the selected angle.
4. The method as claimed in claim 3, wherein the step of stamping the crown
plate comprises forming an opening of larger dimensions than the hosel
tube diameter at the peripheral edge of the crown plate adjacent the heel
of said base, and the steps of securing the crown plate and hosel tube
comprises holding the hosel tube at any selected lie angle with a
predetermined range to the base, welding the hosel tube in place, and
welding the crown plate to the base and hosel tube.
5. The method as claimed in claim 3, wherein the step of securing the face
plate to the base comprises holding the base and face plate together at a
selected loft angle in a holding fixture and tack welding around the
junction between the parts.
6. The method as claimed in claim 3, wherein the step of machining the open
front face comprises machining the side and lower edges to a selected loft
angle in the range from 7.degree. to 22.degree..
7. A golf club head, comprising:
a head base having a sole plate, heel, toe and back wall for a hollow golf
club head of the metal-wood type, the base having an open front face and
an open top face each having a flat peripheral edge, the peripheral edge
of the front face facing forwardly and having opposite sides meeting the
peripheral edge of the open top face at the heel and toe of the base to
form a pair of corner junctions which are substantially co-planar;
the forwardly-facing peripheral edge of the front face comprising means for
machining the open front face to a selected loft angle in a range from
7.degree. to 22.degree.;
a face plate welded across the open front face of the base at the machined
loft angle;
a crown plate having a smooth upper surface with substantially no
protrusions welded across the open top face of the base;
the crown plate having an opening at its outer peripheral edge adjacent the
heel of said base;
a hosel tube extending through said opening into the interior of the head
at a selected angle to a position spaced from the sole plate, the opening
being of dimensions greater than the diameter of the hosel tube by a
predetermined amount and comprising means for allowing a predetermined
amount of tilting of said hosel tube for adjustment of the angle of said
hosel tube prior to attachment to the head, the hosel tube being welded to
the head around the periphery of the crown plate opening at the selected
angle.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to golf club heads of the so-called
metal-wood type, and to methods of making such heads.
Golf club heads of the so-called metal-wood type are well known in the art
for use in place of traditional wooden headed clubs such as drivers,
3-woods, and the like. Metal-wood clubs typically have a hollow club head
formed from cast metal components, such as stainless steel or the like. A
typical cast head is formed by separately casting a sole plate and a
downwardly opening head shell, and then welding the sole plate onto the
cast head shell. The geometry of the metal club head generally is selected
to conform with that of the corresponding wooden headed club. The hollow
interior of the head is often filled with foam or other material to reduce
the "ping" noise resulting from impact with a ball.
Metal-wood club heads are relatively difficult and expensive to
manufacture. Metal casting techniques inherently produce a variety of
surface imperfections, such as pit holes or other blemishes, which are
difficult and time consuming to remove. Excess grinding to remove such
blemishes can adversely affect head weight distribution as well as
structural integrity, and also results in variations in the head geometry
from club to club. Because of this scrap rates as high as 30 percent are
normal in the field, considerably increasing production costs. Even with
these scrap rates, the standard error in loft angle of the striking face
of a cast metal wood club head is typically of the order of .+-.1.degree.,
which can cause a significant difference in operation from club to club.
Another problem is that the casting process is inherently expensive and
does not allow the head geometry to be varied without significant
additional expense. In the golfing field, different individuals will have
different requirements as regards such variables as loft angle, lie or
inclination angle of the club shaft, as well as the amount the striking
face is open or closed (i.e. the angle from toe to heel of the club). Lie
angle is very important when fitting a golf club to a particular golfer.
When the player is striking a golf ball, it is important that the sole of
the club is seated perfectly with respect to the ground. Thus, a taller
player would need to have a shaft with a greater lie angle (more upright)
than a shorter person whose hands will be closer to the ground. The amount
the face of the club is open or closed will also be very important to a
golfer, depending on their experience level, and can be used to control
any tendency to hook or slice the ball. Additionally, variation in the
loft angle or vertical inclination of the face plate is desirable between
stronger and weaker players. A weaker golfer requires more face loft angle
to compensate for lack of club head velocity, whereas strong players
typically prefer a club with less than average loft angle.
Each specific club head having a certain loft angle, shaft angle, and face
angle from heel to toe, typically requires a unique set of relatively
costly casting dies. Thus, several sets of casting dies are needed to
provide even a relatively small range of different club head geometries
which will not be ideal for every individual.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and improved golf
club head of the metal wood type, and a new and improved method of
manufacturing such a golf club head.
According to one aspect of the present invention, a golf club head is
provided which comprises a plurality of components welded together in
assembled relation to define a hollow golf club head of the metal-wood
type, the components comprising a head base having a sole plate, heel, toe
and back wall with an open front face and an open top face, a face plate
welded across the open front face of the base, a crown plate having a
smooth upper surface with no protrusions welded across the open top face,
and a hosel tube secured to project upwardly from the crown plate at any
one of a range of possible angles to the crown plate. The base, face plate
and crown plate are all stamped sheet metal parts.
Preferably, the crown plate has a recess at its outer peripheral edge
adjacent the heel of the base, the hosel tube diameter being less than the
dimensions of the recess and the hosel tube extending through the recess
into the interior of the head, the gap between the hosel tube and
periphery of the recess allowing some free play for angular adjustment of
the hosel tube prior to welding in place. The crown plate is substantially
flat.
The open front face of the base is formed at a predetermined loft angle so
that when the face plate is welded flat against the opening it will have a
corresponding loft angle. The open front face can be machined at a range
of different loft angles to suit different players.
According to another aspect of the present invention, a method of making a
golf club head of the metal-wood type is provided, which comprises the
steps of stamping a head base, face plate and crown plate from sheet metal
material, the head base being stamped to form a sole plate integrally with
a heel, toe and back wall, and having an open front face and open top
face, securing the face plate to the open front face of the base at a
selected loft angle, and securing the crown plate and a hosel tube to the
open top face of the base with the hosel tube projecting at any one of a
range of possible lie angles from the crown plate.
Preferably, the open front face of the base is machined around its
periphery to the desired loft angle, so that when the face plate is welded
flat against the open front face it will be at the same loft angle.
Additionally, the hosel tube is held in the base at the desired lie angle
via an adjustable holding fixture before being secured in place. The crown
plate is subsequently welded over the open front face and secured to the
hosel tube.
In this way, a golf club head can be custom made at little additional
expense to any desired face plate loft and shaft lie angle. The same basic
stamped sheet metal components are used for the entire range of angles,
and are simply adjusted after stamping to achieve the desired angles.
Thus, the same stamping dies may be used for all heads of that particular
number club, regardless of their geometry, considerably reducing
manufacturing expense. All that is necessary to adjust the loft angle
during manufacture is to machine the open front face of the base or shell
before welding the face plate flat against the angled front face. In order
to adjust the shaft lie angle, the hosel tube is held at the desired angle
to the base before securing in place, and the crown plate is then placed
over the open top face and secured in place to complete the assembly. The
crown plate will be formed with a suitable recess for surrounding the
hosel tube, the recess being larger than the tube diameter so that the
tube can extend at any desired lie angle through the crown plate.
The hosel tube front to back orientation relative to the base can also be
adjusted to control the heel to toe angle of the face plate, in other
words to control whether the face plate is open, closed, or normal in the
striking position. Additionally, face progression can be adjusted easily.
This method allows a metal wood to be custom made quickly and easily for
any individual golfer at relatively little additional expense.
The club head will be more uniform and precise in its characteristics than
a similar cast metal-wood club head, since cold stamped sheet metal does
not have the weight variations of a cast metal. As molten material cools,
it contracts, and the amount of contraction will vary both over the area
of the club head and from one club head to the next. This method which
avoids any heating of the metal avoids such problems. The stamping
technique allows the part to have a uniform thickness over the entire face
and the walls can be made thinner than is possible with casted material.
The method also avoids the pit holes and other blemishes which result from
an investment casting process, avoiding the need for excess grinding to
remove blemishes. Thus, the method produces a stronger but lighter club
with more accurate weight distribution than a casted metal-wood. Since
sheet metal is inherently smooth, less grinding and finishing is needed
than with a corresponding casted head which will have more pores and pit
holes.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood from the following detailed
description of a preferred embodiment of the invention, taken in
conjunction with the accompanying drawings, in which like reference
numerals refer to like parts, and in which:
FIG. 1 is a perspective view of an assembled golf club head of the
metal-wood type according to a preferred embodiment of the present
invention;
FIG. 2 is a vertical section of the head taken on the lines 2--2 of FIG. 1;
FIG. 3 is a fragmented horizontal section taken on the line 3--3 of FIG. 2;
FIG. 4 is an enlarged fragmented vertical sectional view corresponding
generally with the encircled region 4 of FIG. 2;
FIG. 5 is an exploded perspective view illustrating assembly of the club
head components;
FIG. 6 is a side elevation view of the head showing some alternative face
loft angles;
FIG. 7 is a front face view of the head showing some of the alternative lie
angles which can be provided;
FIG. 8 illustrates a typical press arrangement for forming parts of the
head;
FIG. 9 is a side elevation view of an assembly fixture for tack welding the
face plate to the base shell;
FIG. 10 is a top plan view of the fixture of FIG. 9;
FIG. 11 is a side elevation view of an assembly fixture for tack welding
the hosel in place in the base shell;
FIG. 12 is a top plan view of the fixture of FIG. 11, the hosel clamp being
omitted for clarity;
FIG. 13 is a view as taken from the left hand side of FIG. 11, with the
hosel clamp omitted; and
FIG. 14 is a sectional view taken on line 14--14 of FIG. 12, showing a
further clamping of the crown plate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-7 illustrate a metal-wood club head 10 according to a preferred
embodiment of the present invention, while FIGS. 8-14 illustrate steps in
a preferred method of making the head 10 according to the invention.
The golf club head 10 is made from several components which are secured
together by welding or the like to form a hollow golf club head of the
metal-wood type, which is then attached to a club handle shaft 12. The
first component of the head is a head base or shell 14 which has a sole
plate 16 formed integrally with a contoured outer wall forming the heel 18
and toe 20 which merge smoothly with back wall 22 of the head. The
resultant base or shell has an open front face with a peripheral rim 21
and open top face with a peripheral rim 23. A substantially flat face
plate 24 is shaped to fit over the open front face of the base and is
welded or otherwise secured around its periphery 25 to the peripheral rim
21 of the front opening of the base, for example via line weld 28 as
illustrated in FIG. 4. The face plate has score lines 29 on its outer,
striking face, which is slightly rounded while the inner face is flat.
A crown plate 26 is similarly shaped to fit over the open top face of the
base but has a recess or opening 30 formed adjacent the heel end of the
head. The crown plate is welded or otherwise secured around its peripheral
edge 27 to the peripheral rim 23 of the open top of the base and to the
top edge of the face plate, so that it extends across the open top face of
the base as illustrated in FIG. 5 but leaves an opening 30 into the
interior of the base. The base, face plate and crown plate are all formed
by stamping from a sheet metal material of suitable strength and
durability, such as stainless steel, titanium, aluminum, brass or the
like.
As illustrated in FIGS. 1 and 2, a hosel tube 32 projects upwardly from the
base through the recess 30 in the crown plate. The handle shaft 12 of the
club is secured in the hosel tube 32 in a standard manner. The hosel is
formed from a suitable metal tubing such as stainless steel tubing having
an inner diameter large enough to fit over the outer diameter of the golf
club shaft 12. The hosel tube is welded around its periphery to the
periphery of recess 30 and to the adjacent regions of the base along its
end which projects into the base via line weld 28 or the like, as
illustrated in FIG. 3, with the external weld region being formed into a
smooth radius in the finished club.
With this arrangement of a club head formed from three stamped sheet metal
parts and a hosel tube, it is relatively easy to make adjustments in the
golf club head geometry by varying the face plate loft angle, the handle
shaft lie angle, and varying the amount by which the face plate is open,
closed or normal in the normal ball striking position FIGS. 8-14
illustrate steps in manufacture of a club head as illustrated in FIGS.
1-7, in which these parameters can be adjusted quickly, easily and
inexpensively during the manufacturing process.
As mentioned above, the base or shell, face plate and crown plate are all
made by stamping from a suitable sheet metal material such as stainless
steel. These parts may be stamped simultaneously from sheet metal 38 in a
progressive forming die 40 as illustrated in FIG. 8. The first blanking
die recess 42 of die 40 is opposed by press 44 which stamps the flat blank
38 in the desired shape. A second forming and embossing die may be used to
form the sole and sides and to mark the part with any desired insignia,
and a third trimming die may be used for shaving off any excess material.
Alternatively, these operations may all be done in three steps or
progressions in a single die. First, the excess material is clipped off.
Subsequently, the base shape is formed and embossed, and finally any
excess material is trimmed off. Alternatively, a pinch off die may be used
to form, emboss and blank the part in one stroke of the press.
FIG. 8 also illustrates the step of stamping the face plate in face plate
blanking die 46 via opposing press 44. The press embosses scoring lines 29
as desired on the striking face during the stamping operation. The crown
plate is suitably stamped in the desired shape and dimensions in a similar
manner.
The hosel is made out of suitable straight cylindrical metal tubing, such
as stainless steel tubing, cut to the desired length and having an
internal diameter sized to fit over the outer diameter of the golf club
shaft.
FIGS. 9-14 illustrate how the four parts of the head are assembled
together. First, the forward margin or peripheral edge 21 of the open
front face of the base is machined or cut back to define the desired loft
angle. The loft angle of a club head, or its tilt from a vertical
orientation, is an important factor depending on the strength and swing
technique, as well as the experience of a player. Basically, the loft
angle will help to determine the backspin, and thus the lift developed on
the ball, so that the ball can stay in the air a longer distance. A weaker
player will require more face loft angle to compensate for lack of club
head velocity and to optimize results. Some players may tend to strike a
ball more on the upswing, and a smaller loft angle can compensate for
this. A driver with less than average loft will be the choice for skilled
players. Thus, heads are normally needed with loft angles in a range from
around 7.degree. to 22.degree., and each head can be custom made to a
specific desired loft angle simply by machining the forward peripheral
edge 21 so that the open front face of the base is at the desired loft
angle.
In order to adjust the loft angle and attach the face plate, the base is
placed in the first welding fixture 48 illustrated in FIGS. 9 and 10.
Welding fixture 48 is designed to hold the face plate 24 against the open
front face of the base while the parts are tack welded together. Fixture
48 includes a base plate 50 from which first and second support posts 52
and 54 project upwardly. The first support post has a nest or recess 56
(see FIG. 10) for locating base 14 with its open front face facing
generally upwardly, and a toggle clamp 58 clamps the sole plate of the
base against the recess to hold the base in position. The second support
post has a pivotal clamping arm or toggle clamp 60 projecting outwardly
towards the first support post. Arm 60 has a recess 62 for locating over
one edge of the face plate 24, and can be locked in any desired angular
position to hold the face plate 24 flat against the open front face of the
base, as illustrated in FIG. 9. Clamping arm 60 is slidably mounted in
rails 64 to accommodate different head dimensions, and is held in a
selected vertical position with a further toggle clamp 66 against the
biassing spring 68.
With this arrangement, any desired loft angle can be accommodated quickly
and easily, simply by first machining the peripheral rim 21 of the open
front face to the desired angle, which may be done with a suitable
grinding tool, for example, while the base is held in fixture 48. The face
plate is then supported flat against peripheral rim 21 and held in place
by arm 60, which is released and pivoted into engagement with the face
plate before locking it in position. At this point, the face plate is tack
welded to the base at the desired loft angle. FIG. 6 illustrates head face
plates 24, 24' at two possible face loft angles, from a substantially
vertical face plate 24 as in solid line for a more skilled player, to a
larger tilt angle of face plate 24' as illustrated in dotted outline in
FIG. 6. With this method, loft angles covering the entire useful range can
be provided as desired, for example at any angle from around 7.degree. to
22.degree..
Another variable in metal-wood club heads is the lie angle, or angle of the
handle shaft. With the arrangement of parts described above, different lie
angles can also be accommodated easily, and a second welding fixture 70 is
provided for this purpose, as illustrated in FIGS. 12-13. Lie angle is a
very important factor when fitting a golf club to a particular golfer. It
is important that the angle between the sole of the golf club and the
handle shaft is such that, when the player is addressing the ball, the
sole plate is flat on the ground. If this is not the case the ball will be
directed to the right or left of the intended line of flight, depending on
whether the heel or toe is elevated. A tall person will therefore require
a greater or more upright lie angle than a short person, whose hands are
closer to the ground.
The four parts making up the club head of this invention are designed to
allow the lie angle to be varied as needed. As explained above, hosel tube
32 extends through opening 30 in the crown plate 26, which is
substantially flat with no protuberances. Opening 30 is of larger
dimensions than the diameter of hosel tube 32, to leave a clearance
between the tube and opening 30 so that the tube can be tilted in the
opening relative to the base, for example between the orientations 32,
32', and 32" as illustrated in FIG. 7. The selected hosel tube orientation
will control the lie angle of the golf club shaft when inserted and
attached to tube 32. The opening 30 must be large enough to allow the
hosel tube to pass through it at any desired lie angle. Thus, the opening
has dimensions equal to or greater than the cross-sectional dimensions of
the hosel tube at the point it enters the base at the desired maximum lie
angle.
The welding fixture 70 illustrated in FIGS. 11-13 is designed to hold the
hosel tube at the desired lie angle orientation while it is tack welded to
the base. As well as allowing the sideways orientation or lie angle of the
tube 32 to be adjusted, fixture 70 also allows the front to rear
orientation of the tube to be adjusted, in order to vary the amount the
face plate of the club will be open or closed when the player addresses
the ball. This can also be a very important factor, depending on the skill
of the player. For example, a built-in closed face can make golfing more
enjoyable to the player who tends to slice his or her drives. A stronger
golfer would want the club face to be "open" a few degrees in order to
compensate for the effect of centrifugal force causing the shaft to bend
forwardly when the club is swung at high speed. Fixture 70, along with the
size of opening 30, allows both of these factors to be adjusted quickly
and easily.
Fixture 70 basically comprises a base plate 72 having a conventional toggle
clamp 74 at one end for extending into the base 14 to clamp the sole plate
in the position illustrated in FIG. 13. A support post 75 projects
upwardly from the other end of the base plate, and a pivotally mounted
locating arm 76 extends inwardly from the support post for engagement with
face plate 24. Locating arm 76 can be adjusted to locate flat against the
face plate 24 at any face plate angle, before locking in place to hold the
base and attached face plate in position. One of a series of different
hosel locating blocks 78 is releasably secured to the base plate via screw
fasteners or the like. Each hosel locating block has an inclined channel
82 on its inner face which is orientated at one of a range of different
lie angles. The lower end 84 of channel 82 is positioned above the heel
end of the base 14, as best illustrated in FIG. 11, and a hosel tube 32 is
positioned in channel 82 to project partially into the base at the desired
angle. The hosel locating blocks will also be provided with different
front to rear orientations to allow clubs to be made with the face plate
open, closed, or normal, with the block in FIGS. 11-13 illustrating a
normal orientation. Once the hosel tube is positioned in channel 82, it is
clamped in place by vise clamp 85, as illustrated in FIG. 11.
Once the appropriate hosel locating block has been selected and the hosel
tube has been clamped in the channel so as to project into the toe end of
the base, the hosel tube is welded in place to the adjacent portions of
the base and face plate. The hosel tube does not need to project into the
base as far as the sole plate, but may do so if additional strength is
required. While the assembled parts are held in the same fixture 70, the
crown plate 26 is positioned over the open upper face of the base as
illustrated in FIG. 14, with opening 30 extending around the hosel tube.
The crown plate is held in position by toggle clamp 86 supported on base
88. The crown plate may also have tabs at its periphery for locating over
the side walls of the base, for easier assembly. The crown plate is then
tack welded around its periphery to the peripheral rim 23 of the open
upper face of the base, and around the periphery of opening 30 to the
perimeter of the hosel tube, with sufficient weld material to fill the gap
between the opening 30 and tube 32.
When everything has been tack welded in place, the club head is welded
around all of the parting lines, making sure it is all welded properly.
There will be an excessive amount of welding to fill in the gaps around
where the hosel connects to the shell, face and crown. This will be
removed and blended into a radius for a uniform look. After welding is
finished, the head is ground off to form an even, smooth finish, such as a
sandblast, bright polish, or tumble finish, or a combination of these
three finishes on different surfaces of the head, as desired. The inherent
smoothness of the sheet metal making up all parts of the head enhances the
finish.
This process has unique advantages over previous processes used to make
metal-woods, since the various parts can be adjusted in the various
welding fixtures quickly and easily to produce different lie angles, loft
angles and face progressions, as well as faces which are open, closed, or
normal. This essentially allows a club head to be custom made to a
particular player's requirements quickly, easily and inexpensively,
without the need for a separate set of investment casting molds for every
different head of a particular number club. This process therefore reduces
tooling costs considerably while at the same time making a much larger
range of different head geometries readily available in each specific club
number.
Another advantage over a casting process is that the club is made of sheet
metal stock, such as stainless steel, titanium, aluminum, brass or the
like. Sheet metal is much less porous than cast metal and is also notably
stronger. There will also be much less weight variation than would occur
in a casting process, resulting in a stronger, lighter club with more
accurate, uniform weight distribution. This process also produces club
heads in which the striking face is orientated to a greater degree of
accuracy. In a cast head, due to uneven shrinkage on cooling, variations
will occur from head to head, and these variations are substantially
reduced in the present method which involves no heating of the metal.
The club head can be stamped and formed out of very thin material, unlike a
cast head, so that the head will be lighter. Thus, this head can be made
larger than normal while still keeping within the weight guidelines of the
PGA. The hollow head interior may be filled with foam, weights, or other
materials to customize head weight, sound and feel characteristics prior
to attachment of the crown plate. For example, metal slugs may be welded
inside the base and face plate in strategic areas to improve the balance
and play-ability of the club. Because of the relatively light weight of
the hollow, thin sheet metal head, such weights can be added without
needing to reduce the size of the head to stay within weight requirements.
With this method, a club head can be ready for shafting in a matter of
hours, unlike the known investment casting process which typically takes a
few days before the head is ready for shafting.
Although a preferred embodiment of the present invention has been described
above by way of example only, it will be understood by those skilled in
the field that modifications may be made to the disclosed embodiment
without departing from the scope of the invention, which is defined by the
appended claims.
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